Balanced slide-valve.



No. 705,730. Patented my 29,1902.

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BVALANCED SLIDE VALVE.

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PATENT l I' FFICE.

JoHN T. w1LsoN,oF-JERsEY` SHORE, PENNSYLVANIA.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent NO. 705,730, dated July 29,1902.

. 4Application iilcd July 13, 1901.

To @ZZ whom, t may concern: j

Be it known that I, JOHN T. WILSON, a citizen of the United States,residing at Jersey Shore, in the county of Lycoming and State ofPennsylvania, have invented new and useful Improvements in BalancedSlide-Valves, of which the following is a specification.

The invention relates to Hbalanced slidevalves, the object being theproduction of Va valve which shall be balanced at all points of itstravel upon the seat, which shall wear evenly and prevent the formationof concavities or irregular surfaces upon the seat or balancing-platethat would allow the passage of motive fluid between the frictionalsurfaces to the exhaust-space of the chest, which can be easily moved,which shall be adapted for application to engines now in use and fortaking the place of inferior types of valves, which shall becomparatively cheap to manufacture and apply, which shall not easilybecome deranged in service, and which, withal, shall constitute asuperior means for performing the requisite functions of a perfectvalve.

With these ends in view my invention consists, objectively, in thecombination, within a chest, of a valve-seat, a movable valve, abalancing-plate having an inclosed space or spaces to which motive fluidis admitted at certain portions of the valves travel and from which itis exhausted at other portions of its travel, and means for holding thevalve to its seat, the said valve only having recipro eating motion andbetween the seat and balancing-plate.

It further consists in certain novelties of construction andcombinations and arrangements of parts herein disclosed, and speciiied.in the claims.

The accompanying drawings illustrate two examples of the physicalembodiment of my invention, one inconnection with an engine` havingexternal admission of motive iiuid and the other having internaladmission and both constructed according to the best modes I have so fardevised for the practical application of the principle.

Figure l is a cross-section in elevation of Fig. 2, taken on the line o:m.` Fig. 2 is a top plan view of a part of the steam-chest of anexternal-admission valve, the cover being re- Serial No. 68,195. (Nomodel.)

moved, so as to disclose thetop of the balancing-plate and the inclosedareas. Fig. 3 is a cross-section'in elevation of an- Ainternal-admissionvalve, taken online :c of the chest and with a balancing-platesubstantially identical with that shown in Fig. 2, one of theringsinclosing the permanent balancing areas being shown in dotted linesat the top.

Referring to the several figures, the letter A designates thevalve-seats, which in both examples are raised some distance above thekbottom of the chest.

B designates the ports to the cylinders.

C is the steam-chest cover.

D designates the walls of the chests; E, the reciprocating valves,having parallel top and bottom faces; F, slots through the valves fromtop to bottom except where the valvestems pass and at the ends, saidslots being of substantially the'same length as the ports to thecylinder; G, the valve-stems; H, the balancing-plates; I, lugs whichhold the balancing-plate central within the steam-chest, said lugs beingin slight frictional contact with the walls D, s0 as to preventhorizontal movements of the plate, but to permit vertical and rockingmovements.

J is a raised or projecting seatupon the under surface of each platewhich corresponds in outline with the valve-seat; K, shallow `pockets inthe surface of the projecting portion which correspond in length andwidth vwith the ports B in the valve-seat; L, permanent balance areas;M, beveled snap-rings inclosing the said areas; N, (see Fig. 2,) beveledsurfaces against which rings M bear; O, pockets which correspond withcentral openings in the valve-seats; P, openings through thebalance-plate and located within the areas bounded bythe snap-rings M,as shown; Q, nclosed spaces or areas ontop of the balancing-plate; R,beveled and jointed snap-rings S, beveled surfaces against which thesnaprings R bear; T, the lap-joints of the rings, and U are openingsfrom the pockets K to the inclosed spaces Q, one or more being present,as occasion may demand.

`In the first example, Figs. l and 2, the permanent balance areas L areopen to the ex haust only, the balance snap-rings M bearing against thebeveled surfaces N and the bot- ICO tom of the steam-chest cover, thusexcluding live motive fluid or steam from the said areas, but allowingthe balancing-plate to move vertically and to rock slightly withoutbreaking the joints. The area of the top of the plate which is to beexcluded from the steam-pressure is determined in any given case byexperiment and should be such as will result in a downward pressure ofthe plate upon the valve great enough to hold the valve in frictionalcontact with the valve-seat and the under surface of the said plate andnot allow the passage of motive fluid to the exhaust.

In the second example, Fig. 3, which illustrates the internal admission,the valve is shortened in length and the snap-rings M and R are beveledon the outside instead of on the inside, as in the first example. Thebeveled surfaces are also reversed, as shown in section and dottedlines, Fig. 3. As the motive uid is at the center of the chest, therequisite downward pressure'of the plate upon the valve is dependentupon the areas L, which are open to live steam, and the size of theseareas must be determined, as in the first example, experimentally.

In both the examples it is obvious that when the parts are assembled andlive motive Huid admitted the downward pressure upon the plate must beample to form steam-tight joints between the valve and the valve-seatandthe lower surface of the top plate.

The mode of operation of the first example is as follows: Assuming thevalve to occupy a central position, as shown in Fig. l, and that itmoves toward the left, the valve remains balanced during its movement tothe position it occupies when about to open the port, for the areauncovered to steam-pres-V sure at the right of the pocket K is equal tothe area covered by the opposite end of the valve at the extreme leftand adjacent the left-hand pocket. Upon the further travel of the valvethe port B is opened and simultaneously the pocket K, and motive iiuidpasses to the inclosed area Q and also downwardly through the slot F,thus allowing a double admission to port B. The lower surface of thevalve which overlaps the port is now subjected to an upward pressure inaddition to the area uncovered at the right ofpocket K, which iscounterbalanced by the steam in the area Q, which area is substantiallyidentical with the area of the steam-port. Steam remains in the area Q,preventing the upward movement of the edge of the balancing-plate untilthe valve in its return travel reaches the edge of the port and point ofexhaust. When exhaust commences from the port B, there is a simultaneousexhaustion of steam from the area Q., and steam from the port can alsopass upwardly through the left-hand slot F and by way of the pocket K ndan outlet into the exhaust-cavity, the slot thus forming a secondaryexhaust-outlet. The left-hand portion of the valve operates in the samemanner as the right-hand portion simultaneously,

The mode of operation of the second example is substantially the same asthat of the first, the only difference being that the valve is of thecentral-admission type, and consequently when the right-hand portion ofthe valve moves toward the right the port B and the inclosed area Qsimultaneously receive the motive fiuid, and when the valve moves towardthe left this motive fluid is simultaneously exhausted from the port andthe inclosed area at the back of the plate. It will be observed that theinclosed areas at the back of the balancing-plate in each example arealways in communication with the ports in the seat, so Jthat whateverpressure of motive Huid or absence of pressure is in the cylinder-portsis also within the inclosed or balancing areas Q. The permanentbalancing of the valve can therefore be effected without regard to theports.

In both examples there is a raised valve- 'seat with ports, a valvehaving parallel faces and slots, and a balancing-plate loosely engagingthe -walls of the chest and adapted to move vertically and also to rockslightly upon the valve.

The top plates each have a lower projecting surface of a form similar tothe valveseat, perlnanent balancing areas at the bacls*` inclosed bysnap-rings, two inclosed areas Q inclosed by snap-rings, and openingsfrom the shallow pockets K to the inclosed areas Q. The modes ofoperation are substantially the same, theadmission of motive fluid to aport and to an inclosed area Qbeing simultaneous and the exhausttherefrom likewise being simultaneous.

From the foregoing it is clear that I have produced a valve whichfulfils all the conditions set forth as the object of my invention,besides possessing additional and desirable features of construction andoperation which will be recognized by persons familiar with the art. Thevalve can be applied to any existing steam-chest. It is practicallybalanced the same in every position of its travel. It will not beexpensive to manufacture and apply, and the :rings above the platehaving no motion will not wear out.

While I have illustrated and described only two examples of the physicalembodiment of my invention, I do not thereby intend'to limit the scopethereof to such examples, inasmuch as the invention can be embodied bydifferent modes and in other shapes. Parts may be omitted, such as slotsin the valve and one of the inclosed areas, and parts lnay be added andthe number of inclosed areas at the back increased. Substitutions may bemadefor example, other means introduced for holding IOG reg

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ing a ported seat, sides, and a cover; of a` inclosed l areas,V andpermanent balancing spaces at theback for holding the valve toits seat.All such and other modifications. lin# tend to embrace within the scopeof my claims. 1 Having described my invention; 'whatjl claim as new, anddesire to secure by Letters Patent, is

1.l The combination with a steam-chest havvalve and a vbalancing-plate;,said "valve"` adapted to reciprocate between the valve-seatV and thelower surface of the balancing-plate; and said balancing-plate having anarea or areas closed to the admission of motive fluid and adapted tomove vertically and Aalso to have a slight rocking motion so as toautomat-` ically take up the wear ofthe frictional sur- ;faces.

"steam-chestcover andvprowvidedhwith a permanent'inclosed balancing areaand with an inclosed'area to which motive 1fluid` is alternatelyadmitted and exhausted by the valve l at dierent portions oftits travel.

4. The combination within a steam-chest,` j

of a ported valve-seat; a reciprocating valve; and a balancing-plate;said balancingplate being adapted topermanently hold the valve to itsseat, andhaving two inclosed areas in;` line with the ports and to whichareas motive; luid is alternately admitted and exhausted.i

5. The combination within a steamchest,`

of a ported valve-seat; a movable valve; aj balancingflplate; and meansfor permanently; balancing the.valve; said `balancimg-plate` having twoinclosed areas, and the parts be-j ing so arranged that when `motivefiuid is admitted to a port it is simultaneously admitted to an inclosedarea and Whenu motive fluidis exhaustedfrom the port itis simultaneouslyexhausted from the inclosed area.

6. The `combination within a steamchest, of a portedvalve-seat; a`movable valve; a

balancingaplate and means for permanently i balancing the valve; saidbalancingfplate having inclosedM areaslat its back `communieating withthelive steam and exhaust, and said valve being slotted; wherebythevalveis balanced at all points of its travel and a double admission anddouble exhaust is secured.

` `7'. The combination within a steamf-chest, t

ofa ported seat; a movable valve; a balancythe balancingplate'and seatto form steamltight joints; landinclosed areas or an inclosed 'area incommunication with the ports or a port at all portions of the valvestravel.

l 8. The combination in a steam-chest, of a ported seat; a movablevalve; abalancingplate; adapted to hold the valve between thebalancing-plate and seat to form asteamtightjoint; and a plurality ofinclosed areas at the back of the plate; the said valve-seat beingraised and the under surface of the balancing-plate being formed with adownf `wardly-extending portion corresponding t the `Vvalveseat. e 9.The combination within a steam-chest, of a ported valve-seat; a movablevalve; a balancing-plate having inclosed areas; and means for eiecting apermanent balance of the valve; the said plate being retained by lugswhich prevent the lateral or longitudinal movement of the same.

10. The combination Within a steam-chest of a seat; a valve; and abalancing-plate; constructed and operated substantially as set forth;the said balancing -Aplatehaving in-v closed areas and pocketscorresponding tothe ports, and openings from the pockets to the.

,inclosed areas.

ll.` The combination within a steam-chest,` of a ported seat; a movablevalve; and a bal ancing-plate located beneath the steam-chest cover;means for effecting a permanent balance of the valve; and means forcounterbalancing the valve when subjected to upward pressure by themotive iiuid Within the ports.

i 12. The combination within a steamflchest, of a ported seat; a movablevalve; a balanc= ing-plate adapted to eect a permanent prese Asure uponthe valve; and means forbalancing y oppositeedges of the plate when saidedges becomeunbalanced.

`Intestimony whereof I aiiix my signature in presence of Vtwo witnesses.

FRANK TRUMP, BRUCE HABLAN.

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